Storage in XenServer
Now that you have an overview of storage technologies and protocols, it is time to introduce the concepts related to storage objects and attributes in XenServer. Storage objects are the following:
Storage Repository (SR)
Virtual Disk Images (VDIs)
Physical Block Devices (PBDs)
Virtual Block Devices (VBDs)
The following figure shows you how the storage objects are presented and how they are related to each other:
Storage Repository (SR)
The main object in XenServer storage is the Storage Repository (SR). This term is used to identify a storage target used by XenServer to store Virtual Disk Images (VDIs), which is the object representing the virtual disk used by a virtual machine.
Generally, the target storage for an SR can be:
Local storage on the XenServer host: An LUN on an iSCSI SAN or an LUN on a Fibre Channel SAN.
Storage through a NetApp or Dell EqualLogic storage appliance: Network File Systems
You can find one or more of these Storage Repository types in a typical XenServer...